ad-aware SE + Symantec Anti Virus Corporate Edition (Not other Syamantec or Norton what-ever-crap-edition)
my niece's PC infected by 1 "downloader" virus gebca.dll (The virus will try to initial connection to internet and download all other crappy virus).
I tried Norton Anti Virus (which shipped with the PC), no luck, virus detected, but can't be removed (file locked).
Install Ad-aware, virus detected, removed and it comes back after reboot.
Install AVG free anti-virus. Virus detected, removed and it comes back after reboot.
Uninstall Norton Anti-virus crappy edition, install Symantec Anti-Virus Corporate Edition Version 10.0, update virus defination (offline), first scanning, virus detected, SAVCE request for a reboot (in order to remove the "downloader" virus) without further scanning. Rebooted, do another round of scanning to remove all other crappy virus downloaded by "downloader" virus.
reboot, and do another round of scanning, the PC is clean and clear.
PS: HiJackthis is good as well.
PS: I think links formated his PC at this time
Symantec (or previously known as Norton) have a lot of version of anti-virus, but the most powerful for client desktop is Corporate edition. Others Edition is just like the car without Turbo, no NOS or with speed cut. Provide you only basic or fundamental function. The other edition may able to detech the virus but can't remove some tought virus.